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Beneficial Bacteria Reduce Urinal Water Use

The Ecoblue Cube, shown here by the drain, can convert conventional flushing urinals to near-waterless operation, while avoiding some of the pitfalls of waterless urinals.

Photo: Ecoblue

Even as lower gallon-per-flush standards have reduced the water use of conventional urinals in recent years, both ultra-low-flush urinals and waterless models have opened possibilities for even greater water conservation. Although urinals that use 1.0 gallon of water per flush (gpf; 6 lpf), or even more, meet relevant codes, these models are now obsolete, environmentally speaking. Yet the expense of replacing them and the perceived risk of installing urinals with newer technology may be too great in many buildings. Now a product using beneficial bacteria promises to convert conventional urinals to virtually waterless operation while also reducing their odor and maintenance needs.

The Ecoblue Cube is a two-inch-square (50-mm-square) block intended to sit on the drain of a standard urinal. It slowly releases bacteria, which multiply and form a biofilm that lines the bowl, trap, and pipes. The bacteria metabolize uric acid, the culprit behind urine odor and uric scale. By reducing or eliminating this odor, the bacteria also eliminate the need to flush after every use. Depending on how the urinal operates and drains, flushing may be necessary just once a day, during regular cleaning.

Lewis Kitts, director of buildings and grounds for the public school in Jamestown, Rhode Island, began using the Ecoblue Cube with eleven 1.6-gpf urinals in March 2006. Kitts’ staff altered the existing manual flush lever so that maintenance personnel can use a simple device to flush, but occupants cannot. Staff flush the urinals twice a day, and clean them daily, as they did prior to using Ecoblue, Kitts said. Using the product, the urinals are “easy to clean and smell good, performance is good, and water use is way down,” said Kitts, whose water bills indicated a 24,000-gallon (91,000-l) savings during the nine months since he started using the Cubes. In addition to saving water, using the Cubes is significantly cheaper than replacing standard urinals with ultra-low-flush or waterless models, “not to mention that you can go back to using water anytime you need to,” said Kitts.

Damian Cox at Ecoblue, the U.S. distributor, said that the product was invented in 1998 in Great Britain, where it has been used successfully in a variety of settings, including military institutions. The Ecoblue Cube uses the bacterium Bacillus subtilis, which is common in soil and has numerous uses, including production of the fermented soybean food product natto and remediation of certain radioactive waste. “It outcompetes the odor-forming bacteria, maintains the hygiene of the urinal, and breaks down organic scale,” said Cox. The Cube also releases a fragrance that masks any odor from the urine itself prior to its breakdown.

The Cube is designed for use with flushing urinals, because flushing clears the debris and sediments that are not digested by the bacteria. Urinals that flush based on a sensor can be adjusted to flush less often, and flush levers can be removed from manual-flush urinals, as in Jamestown. Ecoblue sells the cubes in buckets of 50, at about $8 per cube, said Cox. Since conventional cleaning products will kill the bacteria (they can be quickly reestablished), Ecoblue sells a cleaning product that contains the same bacteria and helps maintain the bacterial biofilm during cleaning. It costs $208 per gallon ($55/l) as a concentrate and is used in a diluted form. A single cube lasts about 1,000 uses, according to Cox, and the Ecoblue Cube breaks even in terms of cost when water is priced at $6–$8 per thousand gallons (3,800 l).

In facilities with urinals that frequently clog due to uric scale, the cost picture may be even better. By metabolizing uric acid, according to Cox, the Cube prevents buildup of scale, which is common in flushing and waterless urinals alike. Uric scale in the drain line is a persistent source of odor even in a well-maintained bathroom, and it can clog waterless or flushing urinals, causing emergency calls to the plumber. Paul Charman, senior conservation planner at the Arizona Department of Water Resources, said that Falcon waterless urinals there had developed odor problems. Ecoblue replaced the urinal cartridges and placed Ecoblue Cubes in the bowls of four of them. Subsequently, Charman told EBN that janitors “[had] to use hardly any water to clean the urinals, and it’s gotten rid of the odor problems,” and he would expand use of the Cube to more urinals. According to Cox, Cube installations like these can extend the life of waterless urinal cartridges indefinitely and eliminate the need for the special trap-sealing fluid. Use of the Ecoblue cleaning fluid can also reduce odor from uric scale buildup surrounding urinals.

On the downside, when EBN staff tested the Ecoblue Cube in our nine-year-old Waterless-brand urinal, some staff complained about the perfume odor from the Cube (although they appreciated the removal of odor from uric scale that had accumulated in the drain and around the cartridge). Our bathroom is very small and lacks continuous ventilation, likely concentrating the perfume. In response EcoBlue offered a Cube with less perfume, which reduced the concern. Overall, the product promises cost savings and environmental benefit with little downside.

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